The Dell AS 501 monitor display comes and goes off in seconds. If I switch off and on again, the display comes back and goes off again in less than a second. I repeat this as many times the same monitor behaves the same. The monitor behaves the same with any other computer too....

make sure monitor is vented properly and not overheating.

Sounds like either there is a bad connection from the computer to the monitor, or the monitor has a faulty power regulator, causing the monitor to overheat prematurely, and shut off.

pa_ma_fi, Have you figured out how to do the flashlight test on you monitor when it's lcd panel turns black or blank n black. No, CCFL back-lit lcd monitors require lots of things to be working all together at once to light up the CCFL tubes. The new style curlie-Q screw-in, energy efficient CFL light bulbs are of the same similar technology and use an "electronic-ballast" circuit to "light-up" the lamp! You will need to check to see if pc is working perfectly with old monitor that you know is good. You should do some free reading here at fixya in my and other fixya ccfl back-lit lcd technicians profiles. ou will also need to visit YOUTUBE for "LCD monitor disassembly" and "LCD monitor repair" videos. May need printed circuit board "switch-mode-power-supply/ ccfl inverter supply " to be repaired If pc software/firmware has been determined not to be causing this on/off/on/off symptom.
12fixlouie

Pleasec look through my albums so you will know what to look for.

Most common failures in the LCD monitors are bad capacitors (bulging top/seal or leaking) in the power supply, failed inverter circuits (blown fuse, shorted transistors, shorted/open transformers), bad lamps (poor solder connections or worn out lamps). You will need to open it up and inspect the inside, see example of failed monitors to get some ideas what to look for: http://s807.photobucket.com/home/budm/allalbums
Post back what you see inside so we can guide you further and it will help out other people in the future also.
http://en.wikipedia.org/wiki/Capacitor_plague

http://www.badcaps.net

Dell bd: http://www.lcdrepair.us

try unplugging your computer and your monitor for about a minute and turn back on. Then see if it works, Good Luck ;)

the sreen tube may be weak to changed or the power switch of the monitor may be faulty and need to be repair with soldering led and a solder.

check ur video card

Monitor is bad for sure. Try another known good monitor on your computer and if the problem stops then you know for sure the original monitor is bad. Hope this helps.

When it goes black, does the power buton stay green or is it orange? If it's orange, the power supply/inverter is your main culprit. If the power button stays green, it sounds like the backlight for the display is bad. Either way, unless you have parts for the same monitor laying around to swap out, you're due for a new monitor. The good news- with the economy in the tank, you can search online and find some reputable vendors selling nicely sized screens for less than $100! Heck, I've even seen a 22" for $129 (once but it was there).

it seems tht the monitor has gone bad & needs to be replaced....try running a monitor self test by unplugging the monitor cable frm the back of the cmputer & make sure the monitor is receving power frm the wall outlet....chk if the monitor displays anything......let me knw if it wrks